Rotary engine



O 6, 1 31-- w. KUHN 1,825,741 v ROTARY ENGINE Filed June 17, 1926 s Sheets-Shoot 1 Oct. 6, 1931. WQKUHN 1,825,741

ROTARY ENGINE Filed June 17, 1926 3 Sheets-Sheet 2 Jnyenfar DI: MYheIn KOhn Af/orney Y Patented Oct. 6, 1931 UNITED STATES WILEELM ran, 01 FBANKFORT-ESCHEBSHEIM, GERMANY ROTARY ENGINE Application filed June 17, 192 6, serlal No. 116,649, and in Germany July 7, 1925.

My invention relates to rotary engines comprising a fiy-wheel arranged concentrically in a cylinder and vanes acting as pistons and guided in radial slots of the fly- 5 wheel. 7

It is an object of my invention to provide more efiicient and reliable means for guiding the vanes. To this endI provide annular races in the casing of the engine adjacent the 10 ends of the vanes which are adapted to receive the usualpins, rollers or slide blocks at the ends of the vanes, and to rotate in said casing. It is well known in the art to which my invention appertains that the problem of satisfactorily controlling the motion of the vanes in rotary engines involves considerable difiiculties on account of the varying conditions under which the means for efiecting such control are operated. For 29 at low speeds the controlling means must impart motion to the vanes while at high speeds, where centrifugal action tends to force the vanes against the inside of the c linder, their motion must be restrained by the controlling means in order to prevent wear of the mating faces and, at any speed the resistance to the reciprocation of the vanes varies during each revolution with the fluid pressure exerted thereon, as obvi- 30 ously the resistance is greater under full fluid pressure than when the vane is relieved from such pressure.

These drawbacks are overcome in my invention by so designing the annular races that they are able to absorb substantially all radial forces exerted on them by the vanes, and by rotatably supporting such races in the casing. In this manner only the comparatively small resultant forces which ocour in the extreme outer end positions of the vanes are transferred to the casing, and due to the interposition of the rotary races between the vanes and the covers of the casing the relative velocities are much reduced at the points of maximum velocity so that the vanes run easily and at minimum wear.

The outer diameter of the races is equal to theinner diameter of the cylinder and their inner diameter is equal to or smaller than far as the inner edges of the vanes.

the diameter of the circle in which move the inner ends of the vanes.

In the drawings affixed to this specification and forming part thereof engines embodying my invention are illustrated diagrammatically by way of example.

In the drawings Fig. 1 is a section along the axis of an engine having shouldered races,

Fig. 2 is a similar section along another @0 radius than in Fig. 1,

Fig.v 3 is an end elevation of the cylinder of the engine, with'the cover removed,

Fig. 4 is an elevation of one of its races, viewed from the inside,-

Fig. 5 is an elevation of the cover which has been removed in Fig. 3, also viewed from the inside,

Fig. 6 is a section on the line VIVI, and

Fig. 7 is a part section on the line VII-- VII in Fig. 3,

Fig. 8 is a transverse section, and

Fig. 9 is an axial section of an engine in which a liner is inserted between the races and'the cylinder, and

Fig. 10 is an axial section of an engine in which the races are integral with the liner.

In all figures identical parts have been indicated by the same reference numerals, 1 being the cylinder barrel, 2 and 3 the cylinder covers, 4 the shaft of the flywheel, 5 and 6 being the vanes which are carried in radial slots 16 of the flywheel. Accessories such as inlet and exhaust ports etc. 5 form no partof my invention and are therefore neither illustrated nor described.

Referring now to Figs. 1 and 2, a race 9 is mounted to rotate freely in a groove in each of the covers '2 and 3 of the cylinder. Each race is U-shaped in section and adapted to receive pins, slide blocks or rollers generally indicated by 8 at the ends of the vanes 6. On the inside the races extend as On the outside they are shouldered and provided with a narrow extension the outer diameter of which is equal to the inner diameter of the cylinder barrel.

The small resultant forces, as mentioned above, occur only in a definite region determined by the eccentricity of the flywheel and the operative positions of thevanes, viz, in the extreme outer end positions of the vanes and as only at these points where such resultant forces are transferred to the casing it is necessary that the bearing rings should tightly fit the covers, the grooves in which the rings are carried may be extended in intermediate positions as shown at 11., so as to connect the grooves in the flywheel 5 in which the vanes 6 are reciprocating, with the cylinder and to enable the operating fluid to circulate about the races, to relieve onesided pressures and to reduce their frictional resistance.

For the same reason it is desirable that the races should be principally supported on their smaller or inner diameters.

Referring now to Figs. 3-7, this engine is equipped with solid races, that is, with races which are not stepped, like the races shown in Figs. 1 and The pins 8 or the like at both ends of the vanes 6 are shown as equipped with rollers 15. In this ma chine the inner diameter of the races 9 is smaller than the diameter of the circle described by the. inner ends of the vanes. Therefore, in order to connectthe slots 16 in thefiy n heel 5 with the cylinder spa 05, holes 10 are made in the races, as best seen in Figs. 4 and G. The bores are within the circles described by the inner ends of the vanes.

The races 9" the covers 2 and 3 tightly only at the points corresponding to the outer and inner end positions of the vanes and therefore at these points, as shown for the cover 2 in Fig. 5, packing faces are provided on the insides of the covers 2 and S at 17 and 18, but otherwise the covers are set back from the faces so that clearances 11 are formed between the inner'faces of the two covers and the outer faces of the corresponding races, as best seen in Fig. 7. These clearances or spaces are connected with the cylinder spaces by recesses 11 of the cylinder 1.

Referring now to Figs. 8 and 9, a liner 12 with perforations 13 is interposed between the cylinder barrel 1 and the 'races 9 by which arrangement, without sacrificing any of the improvements referred to, easy running of the engine is obtained for long periods of duty because the centrifugal forces in the vanes are reliably absorbed by the liner.

er diameter of the race is equal to the inner diameter of the liner machining is facilitated and it is also possible to design the rollers or the like at the ends of the vanes with larger diameter, as will appear from a comparison of Figs. 9 and 10.

The perforations 13 are distributed all over the periphery of the liner 12 which permit access of the driving fluid. Preferably the perforations are so arranged that at the two points where the liner is tightly inserted in the cylinder barrel 1, two adja cent vanes 6 are never registering with two perforations at the same time as otherwise the compartments of the cylinder would be directly connected and considerable leakage would result. As will appear from Fig. 8, the perforations 13 are so pitched with respect to the pitching of the vanes that when one of the vanes is opposite a perforation the succeeding vane is not, and vice versa. Taking by way of example the vane which is in vertical position at the top of the drum in. Fig. 8 it will appear that this vane is opposite a bridge in the liner l2 and at the same time the vane at its left is uncovering one of the perforations 13. The size and pitch of-the perforations are determined in accordance with the eccentricity and the number of vanes, as such direct connections must be prevented in any position intermediate between the maximum and minimum stroke of the vanes. Consequently such perforated liners are only suitable for engines having constant eccentricity, but it will be understood that such limitation is imposed to the liners only, while the races are suitable for constant as well as variable eceentricities.

It will be understood from the foregoing that direct engagement between rotary parts of the engine and the covers occurs substantially only intermediate the shaft and the ends of the vanes, that is within the inner diameter of the races. In this manner the area of the covers is divided into two Zones of different relative velocity. In the outer zone which is constituted by the races and where the circumferential velocities are highest the relative velocities of the vanes in respectto the races and of the races in re spect to the covers, are small, as described, and besides in this zone a less tight fit is required than in the inner zone of smaller circumferential velocities, where a tight fit is required between the ends of the flywheel and the covers in order to prevent leakage along the shaft 4. On account of the comparatively low relative velocities in the outer zone and the less tight fit required here, frictional resistance is much reduced in the zone of larger diameters and consequently higher circumferential velocities, and the efficiency is correspondingly increased. A further important improvement is constituted by the recesses 11, 11', by which con- 1 tact of the races and thevanes with the cylinder barrel and the covers, and consequent friction, is eliminated wherever such contact is not indispensible.

I wish it to be understood that I do not desire to be limited to the exact details of construction shown and described for obvious modifications will occur to a person skilled in the art.

I claim 1. A rotary engine comprising a casing, a fly wheel adapted to rotate in said casing, piston vanes adapted to reciprocate in said casing and in grooves of said fly wheel and to rotate bodily with said fly wheel, races rotatably carried in said casing, and a projection o-ri each of said vanes adapted to engage continuous circular grooves in said races, said races being connected with each otl1er by a Iiner inserted in said casing and adapted to cooperate with the outer ends of said vanes, the outer diameter of said races being equal to the effective inner diameter of said cylinder.

2. A rotary engine comprising a casing, a fly wheel adapted to rotate in said casing, piston vanes adapted to reciprocate in said casing and in grooves of said fly wheel and to rotate bodily with said fly Wheel, races rotatably carried in said casing, a projection on each of said vanes adapted to engage continuous circular grooves in said races, and a liner inserted between said vanes and said casing, the inner diameter of said liner being equal to the outer diameter of said races.

3. A rotary engine comprising a casing, a fly wheel adapted to rotate in said casing, piston vanes adapted to reciprocate in said casing and in grooves of said fly wheel 1nd to rotate bodily with said fly wheel, races rotatably carried in said casing, a projection on each ofsaid vanes adapted to engage continuous circular grooves in'said races, and a liner inserted between said vanes and said casing and integral with said races, the inner diameter of said liner being. equal to the outer diameter of said races.

adapted to fit tightly the outer faces of said races, said end Walls and said casing defining recesses surrounding said races and extend ing between said faces.

6. A rotary engine comprising a casing, a fly wheel adapted to rotate in said casing, piston vanes adapted to reciprocate in said casing and in grooves of, and to rotate bodily with, said fly wheel, end walls at the ends of said casing, races rotatably carried in said end walls, projections at both ends of said vanes adapted to engage continuous circular grooves in said races, 'the inner diameter of said races being not larger than the diameter of the circle described by the inner ends of said vanes, and two faces in each of said end walls at the positions of maximum and minimum stroke of said vanes adapted to fit tightly the outer faces of said races, said end walls and said casing defining recesses surrounding said races and extending between said faces.

In testimony whereof I afiix my signature.

WILHELM KUHN.

4. A rotaryengine comprising a casing,

to rotate bodily with said fly wheel, races rotatably carried in said casing, a projection on each of said vanes adapted to engage continuous circular grooves in said races, and a liner inserted between said vanes andsaid casing and defining perforations so arranged that two adjacent vanes can never register with twoperforations at .a time.

5. A rotary engine comprising a casing, a fly wheel adapted to rotate in said casing, piston vanes adapted to reciprocate in said casing and in grooves of, and to rotate bodily with, said fly wheel, end walls at the ends of said casing, races rotatably carried in said 'end Walls, projections at both ends of said vanes adapted to engage continuous circular grooves in said races, and two faces in each of said end walls at the positions of maximum and minimum stroke of said vanes 

